Sulfur dioxide is an irritant gas that attacks the throat and lungs. Its effect on health is increased by the presence of airborne particles. Prolonged exposure to sulfur dioxide can lead to increases in respiratory illnesses like chronic bronchitis.
Sources of sulfur dioxide
The main sources of sulfur dioxide are coal-fired power stations, smelting of aluminium and other metals, and exhaust from diesel vehicles.
Current standards for sulfur dioxide
The current one-hour, 24-hour and one-year standards for sulfur dioxide are 0.20 ppm (parts per million), 0.08 ppm and 0.02 ppm respectively.
Goal for sulfur dioxide
The one-hour and 24-hour standards should not be exceeded on more than one day per year. The one-year standard should not be exceeded.
How much sulfur dioxide do we detect in Victoria?
Significant concentrations of sulfur dioxide are only detected in Victoria in the vicinity of large industrial sources.
Sulfur dioxide air quality categories
The sulfur dioxide (SO2) data on our website will be shown in different colours, depending on the amount of SO2 in the air. The categories range from green – when levels of SO2 are low and air quality is very good – through to black – when high levels of SO2 result in very poor air quality.
| Air quality category |
SO2 ppb |
| Very good |
0–65 |
| Good |
66–131 |
| Fair |
132–199 |
| Poor |
200–299 |
| Very poor |
300 or greater |